Device for cleaning photographic films and similar articles, especially motion-picture films



M y 1957 E. HAUSDORF ,7 88

DEVICE FOR CLEANING PHOTOGRAPHIC FILMS AND SIMILAR ARTICLES, ESPECIALLYMOTION-PICTURE FILMS Filed June 7, 1955 2 SheetsSheet 1 IN VEN TOR.

' M y 1957 E. HAUSDORF 2,791,788

DEVICE FOR CLEANING PHOTOGRAPHIC FILMS AND SIMILAR ARTICLES, ESPECIALLYMOTION-PICTURE FILMS Filed Juia e 7, 1955 2 Sheets-Sheet 2 Ha. f

XXX (X INVEN TOR.

DEVICE FOR CLEANING PHOTOGRAPHIC FILMS AND SIMILAR ARTICLES, ESPECIALLYM- TEQN-PIQTURE FEMS Erich Hausdorf, Ottawa, Ontario, t'ianadaApplication June 7, 1955, Serial No. 513,741

Claims priority, application Germany Lluiy l, 1954 7 Clmms. (Cl. -100)This invention concerns a device for cleaning photographic films andsimilar articles, especially motion-picture films.

According to the present invention, the device consists of a rotatablyarranged roller or pulley over which the film to be cleaned is guided,whereby the film is subjected only to manipulation by means of rollerswith the exclusion of friction and moisture, the roller means beingcoated with an absorbent substance, which during the guiding of the filmover the cleaning rollers undergoes a change of form similar to thatcaused by a kneading action.

The absorbent substance may conveniently consist of a silicon putty(bouncing putty).

A further feature of the invention resides in mounting the cleaningroller on a pivotal arm on a vertically arranged plate and forming itacross the breadth of a film with a channel for the reception of thesilicon putty coating. When the device is not in use, this coating ofthe cleaning roller can, according to the invention, be covered by meansof a foil-, paper-, or the like strip or by means of a removable sleeve.

The mounting plate for the roller is advantageously formed, according tothe invention, as a revolving plate or disc and is mounted on the baseof the device in such a manner that on insertion of the film into thecleaning device the revolving plate or disc is so rotated that the filmextends in a taut condition between lateral guiding rollers when thecleaning rollers are turned away, but after the revolving plate isturned back into an operative position and fixed relative to the base,the film also becomes wound around the cleaning rollers.

According to a further feature of the invention, two rollers or pulleysare each mounted on a pivotal arm on the vertically arranged revolvingpl te, and each roller possesses a channel corresponding to the breadthof the film, each channel serving for the reception of a coating ofsilicon putty. The two cleaning rollers or pulleys are so arranged onthe revolving plate that on insertion of the film into the cleaningdevice, the plate can be so positioned that the two cleaning rollers lieperpendicularly one over the other and the film runs in a taut conditionbetween the lateral guiding rollers and said two cleaning rollers. Afterrotation of the revolving plate and fixing thereof relative to the base,however, the film becomes wound around the two cleaning rollers in anS-shaped loop.

The device proposed by the invention may advantageously be soconstructed that tension springs engage on the pivotal arms to press thearms against stops, and in the case of excessive tension on the filmprovide for a pendular play movement of the cleaning rollers.

It is also possible within the scope of the invention to mount one ofthe two cleaning rollers directly on the revolving plate and the otherroller on a pivotal arm, whereby the arm is itself pivotally mounted onthe revolving plate and is subjected tot-he action of a tension spPhotographic films and particularly motion-picture films are afflictedwith the disadvantage of dust, dirt, grease spots, oil stains, fibreparticles, finger prints, etc., affecting the transparency of the film,so that frequent cleanin becomes necessary. Trichlorethylene, carbontetrachloride or other grease-solvents in liquid form are suitablecleaning agents; in addition, radio-active substances such as poloniummay be used, which are brought into intimate sliding contact with thefilm.

When using liquid cleaning agents such as carbon tetrachloride, the filmis drawn between two soft surfaces, such as velvet, saturated with thesolution. The dissolving properties of the chemicals used, cause, alongwith the soft rubbing, the removal of foreign bodies adhering to thefilm.

The disadvantage inherent in cleaning with the aid of carbontetrachloride and similar substances is that the film must be moistenedwith the chemicals and thoroughly dried after cleaning before beingrewound. The use of dissolving liquids therefore takes up much time inaddition to which great care must be exercised. The speed at which thefilm can be driven is limited. Although radio-active material such aspolonium will remove the static charge of the film which causes dust,fibre particles or other impurities to adhere thereto it cannoteliminate finger prints, grease spots, oil or similar stains. Anotherdisadvantage inherent in the use of polonium is that it emitsalpha-rays, so that the greatest care must be exercised duringtreatment. Furthermore, radio-active cleaning takes up even more timethan cleaning with carbon tetrachloride and similar substances, a factwhich detrimentally affects the economic factor. It must be remembered,finally, that polonium will only prevent dust, fibre particles, andother foreign bodies from adhering to the film as a consequence of whichsmall brushes or other devices, such as suction devices, must be used inaddition for the removal of the foreign bodies.

It is therefore an object of the invention not only to eliminate thedisadvantages referred to, but also to perform the working process withthe aid of faster and at the same time simplified methods by subjectingthe film conducted over rotating rollers, exclusively to kneading actionwith the elimination of friction or moistening, whereby the kneadingelements are coated with an absorbing substance.

One of the most suitable absorbents is a dimethyl silicone oil mixedwith boric acid and some alcohol to which, after exposure forapproximately two hours to a temperature of 150 C., a filler inapproximately double the quantity is added, whereupon the compound issubected to an approximately similar heat treatment. A compound suitablefor the purposes of this invention may be prepared as follows:

Seventy-five parts by weight of a dimethyl silicone oil is thoroughlymixed with 10 parts of pyroboric acid in a small amount of alcohol andthe resultant mixture heated in an oven for 2 hours at 150 degrees C. Atthe end of this time the mixture is in the form of a quasi-rubbery gel.Forty-five parts of the gel is mixed with parts lithopone and 0.9 partof benzoyl peroxide and worked on rubber compounding rolls until auniform mass is obtained. An additional 45 parts dimethyl silicone oiland 0.9 part benzoyl peroxide is then added, worked into the mass, andthe resultant product heated in an oven at a temperature of to degreesC. for 2 hours. The final product can be worked between the fingers inthe same manner as ordinary window putty, and the more it is worked themore putty-like it becomes. The product also exhibits a high degree ofelasticity or bounce.

The plastic and elastic properties may be enhanced by using boric acidesters. A compound prepared in the following manner is suitable:

A mixture of 200 parts of dimethyl silicone oil, 22.5 ethyl borate and2.3 parts ferric chloride hexahydrate is placed in a suitable containerand steam introduced into the mixture for one-half hour in order tohydrolyze the ester. The resultant product is placed in an oven andheated for 2 hours at 150 degrees C. after which it is worked with 10percent by weight of finely-divided titanium oxide until the desiredputty-like properties have been obtained. The characteristics of thecomposition described herein arise from a balance between thehydrophilic and hydrophobic groups, and the novel material whichpossesses both elastic and plasticproperties is probably a two-phasesystem comprising a highly cross-linked silicone network withhydrophobic methyl groups attached to the silicon. This assumptionconcerning the nature of the composition of the material proposed to beused according to the invention is strengthened by the unusualproperties thereof. t

The friction between hydrophilic and hydrophobic groups is known to behigh. As a result of the friction between these groups when thematerials used for the purpose of this invention are subjected to asudden but not sharp blow, as when dropped on a hard surface, theopposing groups are, for all practical purposes, locked so that thematerial responds as an elastic solid and exhibits a high degree ofbounce. Under sharper impacts, as when struck with a hammer, thematerial behaves even more like a solid and breaks under such an impactwith conchoidal fraction. n the other hand, when it is subjected togradual pressure, as when worked between the fingers, the internalfriction can be overcome so that the material is caused to exhibit itscharacteristic cold-flowing or puttylike properties. Additionalhydrophilic and hydrophobic materials may also be added. For example, alittle glycerine, soapy water, a hydroxide such as zinc hydroxide or afiller such as bentonite which contains absorbed water can be workedinto the material to be used for the present invention in order to reachless elasticity but higher bounce characteristics. On the other hand, ifoleic acid is added in amounts less than one percent, the materialbecomes quite soft, sometimes sticky and the bounce is reduced as theamount of oleic acid is increased. By judicious additions of alternatedoses of oleic acid and glycerine, for example, one can modify theproperties of the material in either direction.

As already set forth, the substance used in this invention has a numberof uncommon physical properties. Among others, it has a very low elasticlimit, so that it will become entirely plastic when distended slowly andwill turn into a fluid if allowed to stand for a while, while it becomesbrittle when distended rapidly. It will nevertheless remain highlyelastic and rebound like a rubber ball. Its specific gravity is around1.1 at a temperature of 20 C.

and it will dissolve in polar organic solutions. It will swell in carbontetrachloride and a great number of aromatic hydrocarbons. It will notcorrode metals.

The silicones employed in this invention offer important advantages inthe cleaning of films as proved by practical tests as well as on thebasis of comparisons with other cleaning agents.

When carbon tetrachloride is used as a cleaning agent, it will take from80 to 120 minutes to clean a 2000' reel of 16 mm. film, while cleaningwith polonium will require from 130 to 150 minutes. But when cleaning iscarried out with the aid of this invention only to minutes will benecessary to clean the same length of film.

The accompanying drawings show one example of how the inventionfunctions but it will be understood that many variations may be made.

In the accompanying drawings:

Fig. 1 is an elevation of the device in operation;

Fig. 2 is a view of a part of Fig. 1, while the film is being inserted;

Fig. 3 is a view similar to that of Fig. 2 after the cleaning rollersembracing the film have begun to pivot;

Fig. 4 is a view to an enlarged scale of a portion of Fig. 1;

Fig. 5 is a section taken on the line V-V of Fig. 4;

Fig. 6 is a cross-section through a film-cleaning roller;

Fig. 7 is a cross-section through a further form of filmcleaning rollerwith a protective sleeve;

Fig. 8 is a partial elevation corresponding to Fig. 4 of a further formof construction and,

Fig. 9 is a section taken on the line IX-IX of Figure 8.

As shown in Fig. l the film for cleaning passes from wind-off reel 2 totake-up reel 3 after passage through the cleaning arrangement. The partsshown in the drawing may be altered as required.

The film 1 running over two rollers 4 and 5 forms an S-shaped loop whichensures the closest contact possible of both sides of the film with thesurface of the rollers. The said rollers 4 and 5 are coated withsilicone as already described.

The said rollers 4 and 5 are mounted on a revolving plate or disc 6 insuch a manner that either one or both of them have some freedom oftransversal movement, so that the film will not break if its speed oftravel between the wind-off and take-up reels 2 and 3 is changedsuddenly. This is an important point owing to the fact that with the aidof this invention the film will be cleaned faster than has been possiblehitherto. Should a high speed not be desired, such as in cases wherecleaning is effected with the aid of the present device and method incombination with an examination of the film, the said rollers 4 and 5may be mounted directly on revolving plate 6 without any freedom oftransversal motion.

The said revolving plate 6 is mounted on a base or support member 7provided with comparatively large-headed cap screws 8 and 9 by means ofwhich the said revolving plate 6 may be locked or released for turning.

The base 7 is provided with two extension flanges 10 and 11, on whichguide-roller pairs 12, 13 and 14, 15 are mounted, and to which may befastened at the same time supports 16 and 17 by means of screws orsimilar fasteners 18. The said supports 16 and 17 are aflixed to a baseplate 20 by means of screws 21 and 22, which base plate mayadvantageously form a support for a standard device for winding upfilms. In addition, brackets 23 and 24 for reels 2 and 3 are mounted onthe said base plate 20.

Should the film 1 have a thick coating of dust or fibre particles, anadditional cleaning device, such as a radioactive one, may be used toadvantage. To that end polonium applicators 27 and 28 may be arranged onboth sides of film 1 on base 7 or the flange 10. These additionalinstallations do not affect the essential points of the invention andare to be considered only as supplementary.

Before inserting the film 1 into the cleaning device, the revolvingplate 6 is turned counter-clockwise into the position shown in Fig. 2,so that the roller 4 comes to rest directly under roller 5. In thisposition the film will run between guide rollers 12 and 13, cleaningrollers 4 and 5 and guide rollers 14 and 15. Thereupon the saidrevolving plate 6 is moved clockwise past the intermediate position asshown in Fig. 3 until the final cleaning position shown in Fig. 1 hasbeen reached. The heads of screws 25 and 26 that hold rollers 4 and 5may be sufliciently large so that revolving plate 6 may be easily turnedwith the fingers by means of the said screw heads.

Figs. 6 and 7 show two different designs for the said rollers 4 and 5.The said rollers should be provided with a groove 29 which is to containthe silicone cleaning compound 30 according to this invention. The bore31 of the roller core 32 receives bearing and fulcrum pin 33 which isscrewed into bearing arm 34 or 35 as the case may be, which arm inturnis swivelled to revolving plate 6 by means of screw 36 or 37. The screws25 or 26 as the case may be maintain the rollers 4 and 5 on bearing pin33.

It must be remembered that the cleaning compound 30 would flow oifrollers 4 or 5 when the device is not in operation. It is thereforeadvisable to place a strip of paper, foil, or other similar materialover the rollers 4 and 5 when the device is not running, so as to retainthe cleaning substance 34) in position. It is best to store the devicein a cool place when not in use.

As shown in Fig. 7 it is also advantageous to push sleeves 38 overrollers 4 and 5, the said sleeves being easily removable with the aid ofcollar 39. In that case the forward guide flange of rollers 4 and 5 doesnot corbel out above the cleaning preparation 30. The film 1 is guidedlaterally to a suflicient extent by guide rollers 12 to 15.

Owing to its consistency, the cleaning compound 30 may be applied easilyto rollers 4 and 5. It will be superfluous to knead in the substancecarefully since it will be distributed evenly over the rollers 4 and 5within groove 29 after a few turns.

As shown in Figs. 4 and 5, the rollers are mounted in an easilypivotable manner on revolving plate 6 by means of pivot arms 34 and 35and bearing screws 36 and 37. The pivot arms 34 and 35 strike stops 40and 41 mounted on the said revolving plate 6, the said stops preventingfurther clockwise pivoting. Small springs 42 and 43 affixed to pins 44and 4S draw the levers 34 and 35 outward counterclockwise, whereby therollers 4 and 5 in conjunction with stops 40 and 41 are maintained inthe position shown in Figs. 1 and 4. However, the labile bedding has theadvantage of enabling the lever 34 to move clockwise when the film 1 ispulled too tight between wind-oflf reel 2 and roller 4, thus preventingthe film from breaking.

In many cases it is possible, if desired, to provide only one pivotalroller, as shown in Figs. 8 and 9. Only the roller 5 is here shown asmounted on the pivot arm 35, whilst the roller 4 is mounted rotatablydirectly on the revolving plate 6.

Instead of cap screws 8 and 9 that hold the revolving plate 6 fast tothe base 7, any other retaining means serving the same purpose, such asresilient clamp, may be used. According to Figs. 8 and 9, only onecentral clamping screw 46 is utilised, and an opening 47 in the swingingarm 35 is provided in order to make possible actuation of the screw 46.

The drive of the film take-up spool 3 may be eifected by hand by meansof the crank 48 (as in Fig. 1) or by means of a motor.

Owing to the remarkably efficient cleansing eifect of compound 30, thefilm may be wound oflE at high speed, namely at the rate of from100'-400' per minute. The silicone coatings will swallow up practicallyall the dirt or dust from both sides of film 1. No friction what soeveroccurs between the surfaces of the film and the cleaning compound sothat the film will never be damaged in the slightest degree. Cleaningrather takes place through a continuous change in form, comparable tokneading of the compound 30. In spite of the very short contact betweenall the smallest parts of the film surfaces and the coating a thoroughcleaning action consequently takes place, which may be supplemented orenhanced as desired by a preceding or subsequent treatment with knowncleaning processes. will be superfluous.

But normally this measure Although particular reference has been' madeinthe foregoing description to film and particularly photo graphic film,the invention has a wider scope. With the aid of this invention anysurface of Celluloid or cellulose acetate as well as any other substancehaving a smooth surface, such as steel tape, wire, string, glass plates,etc., may be cleaned as described herein.

Apart from the remarkable cleaning action of the compound 30, mentionmust be made of the additipnal 6 and considerable advantage of the saidcompound being easily changeable and obtainable at low cost;furthermore, the same coating may be used for a surprisingly longperiod.

I claim:

1. A device for cleaning smooth-surfaced articles, comprising at leastone rotatably arranged roller, means for guiding an article to becleaned over said roller in intimate contact therewith, and an absorbentcoating on said roller, said coating undergoing, during guiding of saidarticle over the roller, a change of state similar to that caused by akneading action, whereby said article is subjected only to amanipulation by said roller without the use of friction or moisture,said roller being formed with a circumferential channel for thereception of said coating, and means in said device for covering saidabsorbent coating on said roller when not in use, adapted to retain thecoating in said channel.

2. A device as set forth in claim 1, wherein said retaining means forthe roller in the channel is a removable sleeve.

3. A device as set forth in claim 1 wherein the width of the channel iscommensurate with that of the article to be cleaned.

4. A device for cleaning smooth surfaced articles, comprising a supportmember, a vertically disposed revolving plate arranged within saidsupport member, at least one pivotal arm mounted on said revolvingplate, a cleaning roller carried rotatably on said arm, said rollerbeing formed with a circumferential channel, means for guiding anarticle to be cleaned over said channel, a coating in said channel of amaterial which undergoes a change of state similar to that caused by akneading action when said article is passed thereover, lateral guiderollers disposed on the support member on either side of the revolvingplate, means for biasing said arm towards the periphery of said plate,and means for clamping said plate in a fixed position relative to thesupport member, whereby during insertion of the article into the devicethe revolving plate is turned to move the cleaning roller away from thepath of said article between said guide rollers, and is then turned andclamped relative to said support member in a position effecting intimatecontact of said cleaning roller with said article, the pivotal armbiasing means serving to maintain said pivotal contact.

5. A device for cleaning photographic film, comprising a mounting plate,a support member carried by said mounting plate, a vertically disposedrevolving plate arranged within said support member, a pair of pivotalarms arranged in spaced relationship on the revolving plate, a cleaningroller carried rotatably on each arm, said rollers each being formedwith a circumferential channel, a coating of silicon putty in eachchannel, lateral guide rollers disposed on the support member on eitherside of the revolving plate, means for biasing said arms towards theperiphery of said plate, and means for clamping said plate in a fixedposition relative to said support member, whereby on insertion of thefilm into the device the revolving plate is turned to cause the cleaningrollers to lie perpendicularly one above the other, so that said filmextends between said rollers and between the lateral guiding rollers,when the revolving plate is turned and clamped relative to the supportmember to cause the film to become wound around-said cleaning rollers inan S-sl1aped loop in intimate-Yeoman with said putty, said pivotal armbiasing means serying to maintain said intimate contact.

6. A deviceas set forth in claim 5 wherein the revolving platecarries-stops limiting the pivotal movement of the pivot arms. and saidbiasing means comprise tension springsurging said arms against saidstops whilst permittinga pendular play of said arms in the event ofexcessive film tension.

7. A device for cleaning photographic film, comprising a mounting plate,a support member carried by said mountin'gplate, a vertically disposedrevolving plate ari 7 ranged within said support member, a pivotalarm'arranged on the revolving plate, a first cleaning roller arrangedrotatably on said pivotal arm, a second cleaning roller rotatablymounted directly on said revolving plate, said rollers each being formedwith a circumferential channel, a coating of silicon putty in eachchannel, lateral guide rollers disposed on the support member on eitherside of the revolving plate, means for biasing said arm towards theperiphery of said plate, and means for clamping said plate in a fixedposition relative to said support member, whereby on insertion of thefilm into the device the revolving plate is turned to cause the cleaningrollers to lie perpendicularly one above the other, so that said filmextends between said rollers and between the lateral guiding rollers,when the revolving plate is turned and clamped relative to the supportmember to cause the film to become wound around said cleaning rollers inan S-shaped loop in intimate contact with said putty, said pivotal armbiasing means serving to maintain said intimate contact.

References Cited in the tile of this patent UNITED STATES PATENTS1,189,633 Shue July 4, 1916 2,256,744 Lincoln Sept. 23, 1941 2,541,851Wright Feb. 13, 1951

